Railway signaling system



J. C. FIELD.

RAILWAY SIGNALING SYSTEM.

APPLICATION FILED DEC. 30. 1919.

1,434,77, Patented. Nov. '7, 1922.

v Z L30 5 Patented Nov. 7, 1922.

UNITED STATES PATENT OFFICE.

JOSEPH C. FIELD, OF OR ANGE, NEW JERSEY, ASSIGNOJR T0 WESTERN ELECTRICCOMPANY, INCORPORATED, OF NEW YORK, N. Y., A CORPORATION OF NEW YORK.

RAILWAY SIGNALING SYSTEM.

Application filed December 30, 1919.

T 0 all whom it may concern:

Be it known that I, JOSEPH C. FIELD, a citizen of the United States,residing at Orange. in the county of Essex and State of New Jersey, haveinvented certain new and useful Improvements in Railway SignalingSystems. of which the following is a full, clear, concise, and exactdescription.

This invention relates to selective signaling systems and particularlyto the class known as train despatching systems.

One object of this invention is to provide a system whereby a despatcheror an attendant at a central station may determine when a train or cararrives at or passes a particular track section, and means whereby ananswer-back signal may be transmitted. from a way-station andpermanently recorded at the despatchers station.

A further object is to provide means whereby a despatcher or anattendant at a central station may signal a trainman to execute certainorders upon arriving at a predetermined track section.

Other objects of this invention are to simplify the way-stationequipment by eliminating relays as much as possible and substitutingtherefor motor driven cams and code wheels which make apparatus morepositive in action and require less maintenance.

In accordance with this invention there is provided a signaling system,the circuit of which extends from a central or despatchers station alonga railroad track divided into sections. ,With certain sections of thetrack are associated signal-sending devices set in condition foroperation from the central station, the passing of a train or car intothe section causing the signalsending device to send signals to thecentral station, where such signals are recorded by a suitable recordingdevice. More specifically the invention contemplates the employment ofmotor operated cam discs at a way-station for setting the signal-sendingdevice in condition to be operated by the entrance of a train into theassociated track section, and a local source of current intermittentlyconnected with the line by means of code wheels for causing theoperation of a suitable recording device at the despatchers station.Furthermore the invention contemplates the employment of additionalmeans at a way-station under control of the central station despatcherfor setting a sigsection C.

Serial No. 348,330.

nal indicating device at a way-station. which, when set to its operativeposition, will provide a distinctive code answer-back, indicating theposition of the signaling deylce, and means whereby when the indicatmgdevice is restored to normal or its unactuated position. anotherdistinctive code answer-back will be provided.

Referring to the drawings, Fig. 1 is a diagram of the apparatus andcircuit connections of a railway signaling system wherein the centraloffice despatcher is apprised of the entrance of a train into, or thepassage of a train through. a particular track section. The apparatusand circuit a arrangement of Fig. 2 1s simllar to Fig. 1,

except that a signal indicating device is shown at a. way-station whichis adapted to be operated and restored to normal by the central officedespatcher. Fig. 3 represents an alternative arrangement of the systemdisclosed in Fig. 1.

In Fig. 1 the way-station selectors are controlled over a metalliccircuit and the central station recording mechanism is also controlledover a metallic circuit. In Fig. 2 the way-station selectors arecontrolled over a metallic circuit while the central office recordingmechanism is controlled over a simplex circuit. In Fig. 3 theway-station selectors are controlled over a simplex circuit and thecentral office recording mechanism is controlled over a metalliccircuit.

Referring to the drawings, and particularly to Fig. 1, A designates acentral or receiving station and B a way-station associated with asection C of a railroad track along which extends line wires 10 and 11connected to the receiving or central station A.

Located at the central station is an impulse transmitting device 12 forsignaling the Way-station associated with the track- An impulsetransmitting device 13 is shown at the central station which may beemployed to signal a Way-station asso- I ciated with section D of therailroad track. It will be understood that any number of impulsetransmitting devices may be employed for controlling apparatus at anynumber of Way-stations. For the sake of simplicity, only one way-stationand two impulse'transmitti'ng devices are shown.

At the transmitting station A there is a main battery 15 for supplyingcurrent for operating the selectors at the Way-stations. This battery isnormally disconnected from the line wires and 11 and may be'connectedtherewith by the operation of a relay 16. A pole changing relay 17 isalso pro-- vided for reversing the connections from battery to the linewires. The relays 16 and 17 are connected in parallel and in circuitwith a local battery 18 and are controlled by the impulse transmitters12 and 13. Each impulse transmitter is provided with cam surfaces andteeth for controlling contact springs and 21, which are in circuit withthe pole changing relay 17. The free end of contact spring 20 oftransmitters 12 and 13 is bent downward and normally rests in a notch inthe transmitter discs and is normally out of engagement therewith.During rotation of a transmitter disc, in the direction of the arrow,contact spring 20 is in engagement with the disc, thereby maintainingthe circuit of relay 16 closed to connect battery 15 to the line wires10 and 11. Assuming that impulse transmitter 12 is operated. as the discthereof starts to rotate, the circuit of relay 16 is completed operatingthis relay and connecting battery 15 to the line wires.- As contactspring 20 rides upon the first tooth, it also engages contact spring 21to actuate the pole changing relay 17 by current from battery 18 toreverse the connection of battery 15 to the line wires. \Vhen spring 20drops between two teeth, relay 17 will be deenergized, and during thetime spring 20 is passing over the second tooth, the pole changing relay17 will again be actuated to again reverse the connection of battery 15to the line wire. As the transmitter disc continues to rotate,alternating impulses are sent over the line wires. It will be readilyunderstood that as the transmitter disc rotates and spring contact 20passes over and between the teeth of thetransmitter disc, alternatingimpulses of substantially equal length will be transmitted, and duringthe time the contact spring 20 leaves the last tooth of one group andengages the first tooth of another group, a prolonged impulse ofpredetermined polarity is sent over the line wires. When the transmitterdisc has completed a revolution, the contact spring 20 drops into thedepression 22, thereby opening the energizing circuit of relay 16 toremove battery from the line wires and permit the release of theselector at the selected station.

A selector is provided at the Way-station which may be of the type shownin my Patent No. 1,200,095, dated October 3, 1916. Such a selector isadapted to respond to the actuation of impulse transmitter 12 and would,in this instance, respond to a code of impulses represented by 3-24-12.The spaces between the several groups of teeth on the impulsetransmitters are for the purpose of providing suitable time intervals ofsufiicient duration to permit the contact arms of all selectors on theline, except the desired one, to release before the first impulse of thesucceeding set is transmitted.

The selector 25 at way-station B, beim bridged across the line wires 10and 11, will respond to the alternate impulses sent out by the operationof impulse transmitter 12 to cause the selector 25 to' move contact arm26v into an engagement with contact 27. The closure of contacts 26 and27, although only momentary, establishes an operatin circuit for motor30. The instant this circuit is established and before the selectorcontacts 26 and 27 are opened, the motor has advanced the control wheelan amount suffi cient to close contacts 35 and 41, which are connectedin parallel with the selector contacts, thereby continuing the operationof motor 30 until the control wheel 10 has made approximately one-half arevolution, when the contacts 35 and 14 will be broken and the motorstopped. During the first half revolution of motor driven cam shaft 136,the contact springs 65 of code wheel 70 are operated and a circuit iscompleted from line wire 10. conductor 28 through control wheel +10,contact spring 35, local battery 31, armature 32 and front contactthereof of track relay 33, contacts of control wheel 50, con tacts ofcontrol wheel 70, conductor 29 to line wire 11. The impulse relay 16 atthe central station now being deenergized. the line wires 10 and 11 areextended through the back contacts of the armatures of relay 16 to theelectromagnet 19. The electromagnet 19 in its operation controls theoperation of a suitable recorder connected in a local circuit includingbattery 23, armature 24 and front contact of magnet 19. Thus, theinstant a way-station is selected, characteristic code impulses may besent from the waystation by code wheel and local battery 31 to operate asuitable recorder at the dospatchers station which may produce apermanent record of each closure of the circuit through magnet 19. Inaccordance with the teeth out on the lower half of code wheel 70, therecording instrument should record symbols 22-4. indicating that theWay-station circuit is in condition for receiving an answer-back,commonly known as an OS signal, when a train arrives at that particulartrack section.

'W'hen a train enters the track section C, the track relay 33 isshort-circuited, thereby releasing the same. Track relay 33, upon beingdeenergized, releases armatures 32 and :34, thereby closing backcontacts 36 and 37. The closure of contacts 37 completes an operatingcircuit through motor 30 from local battery 31, armature 3-1 of trackrelay 33, contacts 37., contacts 38 of control wheel 50. which are nowclosed due to control wheel 50 having completed one-half of arevolution, series field 39, armature of motor 30 to the other side oflocalbattery 31. The m0- tor 30 will then operate to rotate the. camshaft 36. After the control wheel 50 has been rotatedonly a few degrees,the contacts 38 controlled thereby will be broken. but owing to the factthat control wheel 40 has been rotated a sufficient amount to closecontacts 35 and 44, the operating circuit for motor 30 will not bebroken until control wheel 40 has completed the remaining onehalf of arevolution. \l'hilethe cam shaft 136 is turning through the last half ofa revolution, an answer-back circuit is completed in substantially thesame manner as the one previously traced, except that code wheel 60 isnow employed instead of code wheel 70, and by reason of the alteredarrangement ofthe teeth, a distinctive code answer-back is transmittedto indicate that a train has arrived at the track section t. This lastmentioned answer-back circuit may be traced from line wire 10, conductor28, control wheel 40, contact spring local battery 31, armature 32 andback contact 36 of track relay 33, contacts of code wheel 60, conductor29 to the other line wire 11. Since the code wheel 60 is provided withteeth arranged in groups of 223, the

magnet 19 at the despatchers station will be energized and deenergizedin proper sequential order to, in turn, cause the record 2-23 to berecorded by the recording device.

The instant cam shaft 136 has completed one-half a revolution, contacts35, controlled by wheel 40, will be opened, thereby opening theenergizing circuit of motor 30, to thereby stop the motor and leave thecontrol and code wheels, mounted on shaft 36, in the positions shown inthe drawings. As soon as the train passes out of track section 0, trackrelay 33 will again be energized, thereby placing the apparatus againunder the control of the central oflice despatcher.

Referring to Fig. 2. the apparatus and circuit arrangement of thedespatchers equipment are similar to the central otlice equipment justdescribed, and the way-station equipment is substantially the same asthat previously described, except that a signaling device 75 is shown inplace of the contacts controlled by the track relay 33. If it is desiredto operate the signal 75, shown in Fig. 2, the central otfice despatchermay operate the calling key or impulse transmitter 12 to operate theway-station selector 25, as previously described, to cause the selectorcontact arm 26 toengage the contact 27, thereby completing an operatingcircuit through motor 30. The instant motor 30 begins rotating, controlwheels 80 and 90 and code wheel 95 will commence rotating in thedirection of the arrow. A slight rotation of control wheel 80 will causethe closure of contacts 81 thereby maintaining an operating circuit fromlocal battery 31 through the motor 30. A slightrotation of control wheel90 will cause the closure of contacts 91 and will complete an operatingcircuit through the signal 75 including local battery 31, which is inparallel with the motor circuit. As soon as signal 75 has been set oroperated by-the closure of its energizingcircuit, code wheel 95 willcause the intermittent closure of contacts 96, sending impulses to thedespatcher-"s station from ground at the way-station through the battery31 and over the metallic conductors 10 and 11 in parallel to ground atthe despatchers station, employing what is termed a simplex circuit, i.e., one in which electric current flows over two conductors in parallelwhich are parts of asecond circuit (the. full metallic circuitcomprising conductors 84, 85, 10 and 11) without disturbing the currentflowing in the second circuit or being disturbed by the current flowingtherein. This circuit may be traced from ground at contacts 96 throughthe battery 31, contacts 81, control wheel 80, contacts 82 controlledthereby over conductors 84 and 85 in parallel to line wires 10 and 11,through the armatures and back contacts of impulse relay 16, and thewinding of magnet 19 to ground, thereby operating the recordingmechanism as hereinbefore described. In this instance, and in accordancewith the arrangement of teeth on the code wheel 95, the record 2- 21should be recorded by the recording mechanism, thereby indicating thatthe signal 75 is set. This signal 75 may be employed for any desiredpurpose, .for example, to authorize a trainman to take asiding, call upthe central office despatcher by telephone, etc.

After the trainman has responded to the despatchers signal and it isdesired to restore the signal to its normal position, the despatcher mayagain operate the impulse transmitter 12 to restore the signal tonormal, and, at the same, time, receive a distinctive code answer-back,indicating that the signal has been so restored. This may beaccomplished by the despatcher operating the impulse transmitter 12 asecond time to cause the selector 25 atthe way-station to again completethe operating circuit of motor 30. The shaft 136, in completing the lasthalf of its revolution will, through the rotation of control wheel 80,close contacts 81 and contacts 82, and through the rotation of controlwheel 90, contacts 91 will be opened to release the signaling device 75;Code wheel 95 will open and close contacts 96 in accordance. with theteeth arrangement on the upper portion of the code'wheel, as

shown, to send adistinctive code answerback to the despatchers stationover the circuit hereinbefore traced. The code signal in this instancewill be 2-22 which will be permanently recorded by the recordingmechanism at the despatchers station under the control of theelectromagnet 19.

The apparatus and circuit arrangement disclosed in Fig. 3 aresubstantially the same as the arrangements disclosed in Figs. 1 and 2.In Fig. 3 the way-station selector is operated from the despatchersstation over a simple-x circuit, while in Figs. 1 and 2, the way-stationselectors are operated over a full metallic circuit. In Fig. 3 theanswerback recording mechanism is operated, as in Fig. 1, over a fullmetallic circuit and unlike the answer-back recording mechanismdisclosed in Fig. 2, which is operated over a simplex circuit.

In series with the line wires 10 and 11 are inserted retardation coils47 and 48 respectively, which are bridged by means of a condenser 49.The retardation coils and the condenser are for the purpose ofgraduating or smoothing out the current impulses from the impulse relay,in order that they will not cause a disagreeable thump in telephonicapparatus which may be connected with the line Wires during thetransmission of the signaling impulses.

In each of the figures of the accompanying drawings the cam and codewheel shaft 186 is shown directly connected to the motor 30for'simplicity of illustration. It is to be understood, however, thatany suitable means may be provided. for driving the shaft 136 from themotor 30, and that in actual practice a set of reducing gears wouldprobably be employed in order that the shaft 136 might be run at a speedconsiderably less than the speed of the driving motor. Furthermore anysuitable driving means may be used in place of motor 30, for example,

'a step-by-step mechanism which automatically opens and closes its owncircuit.

hat is claimed is:

1. In a railway signaling system, a central station, a way-station,selectively-operated circuit-closing means at said way-station,impulse-sending means at said central station controlling the operationof said selectively-operated means, a circuit controlled by saidselect-ively-operated means, electrical driving means in said circuit; aplurality of answer-back operating means at said way-station controlledby said driving means, each of said answer-back operating means adaptedto send a different and distinctive series of answer-back signals tosaid central station, and means controlled by said electrical drivingmeans for stopping the operation of each of said answer back operatingmeans.

2. A railway signaling system comprising a railroad track divided intosections, a central station, a simplex circuit and a full metalliccircuit extending from the central station to a track section, asignal-sending device associated with said track section and operableelectrically to send a code signal over the metallic circuit to thecentral station, means rendered effective by the en trance of a traininto said track section for causing operation of the signal-sendingdevice when that device is in a particular condition, and meansselectively controlled over the simplex circuit from the receivingstation for placing said signal-sending device in said particularcondition.

3. A railway signaling system comprising a railroad track divided intosections, a central station, a way-station associated with one of saidsections, a line circuit extending from said central station to saidway-station, a motor at said way-station, means controlled from saidcentral station for starting said motor, means actuated by said motorfor sending a code signal back to the central station, a cam operated bysaid motor for stoppin it, a'second cam operated by said motor, an meanscontrolled jointly by said second cam and by the entrance of a traininto the track section associated with said way-station for causing theoperation of said motor and the code signal actuated thereby.

4. A railway signaling system comprising a railroad track divided intosections, a central station, a way-station associated with one of saidsections, a line circuit extending from said central station to saidway-station, a. motor at said way-station, means controlled from saidcentral station for starting said motor, means actuated by said motorfor sending a code signal back to the central station, a cam operated bysaid motor for stopping it, a second cam operated by said motor andmeans controlled jointly by said second cam and by the entrance of atrain into the track section associated with said way-station forcausing the operation of said motor and the code signal means actuatedthereby.

5. A railway signaling system comprising a railroad track divided intosections, a central station, a simplex and a full metallic circuitextending from the central station to a track section, a motorassociated with said track section and when operated adapted to actuatemeans for sending a code signal over the metallic circuit to the centralstation, means rendered effective by the entrance of a train into saidtrack section for starting said motor, and means selectively operatedover the simplex circuit for starting said motor.

' 6. A railway signaling system comprising a railroad track divided intosections, a cen tral station, a simplex and a full metallic circuitextending from the central station to llU a track section, a motorassociated with said track section and when operated adapted to actuatemeans for sending a code signal over the metallic circuit to the centralstation, means rendered effective by the entrance of a train into saidtrack section for starting said motor, and means selectively operatedover the simplex circuit for starting said motor to actuate a differentmeans for sending a different code signal to the central station.

7. A railway signaling system comprising a railroad track divided intosections, a central station, a simplex and a full metallic circuitextending from the central station to a track section, a motorassociated with said track section and when operated adapted to actuatemeans for sending a code signal over the metallic circuit to the centralstation, means rendered effective by the entrance of a train into saidtrack section for starting said motor, and means selectively operatedover the simplex circuit for starting said motor to actuate a differentmeans for sending a different code signal to the central station, andmeans controlled by said motorv for stopping it.

8. A railway signaling system comprising a railroad track divided intosections, a central station, a simplex and a full metallic circuitextending from the central station to a track section, a motorassociated with said track section and when operated adapted to actuatemeans for sending a code signal over the metallic circuit to the centralstation, means rendered effective by the entrance of a train into saidtrack section for starting said motor. and means selectively operatedover the simplex circuit for starting said motor to actuate a differentmeans for sendinga dilferent code signal to the central station, andcommon means controlled by said motor for stopping it when startedeither by the selectively operated means or by the entrance of a traininto said track section.

In Witness whereof, I hereunto subscribe my name this 27th day ofDecember A. D., 1919.

JGSEPH C. FIELD.

